Tumor Causes Chiari And A Syrinx

Case Studies is a feature designed to highlight interesting patient cases reported in the research. Given the lack of knowledge about CM/SM, much of the published research comes in the form of case studies - doctors describing one or two patients they have seen and treated - as opposed to rigorous scientific studies. While this type of publication doesn't advance the scientific cause as much, it does give us a window into some of the issues surrounding CM/SM, including lasting side effects and related conditions. And hopefully, some of our readers will say, "Hey, that's just like me!" and know they are not alone in what they are going through.

CASE 1: Tonsillar Herniation And Syringomyelia Secondary To Posterior Fossa Tumor

Reported In: British Journal of Neurosurgery, February 2004
Doctor: Bhatoe, Dept. of Neurosurgery, Army Hospital, Delhi Cantt, India

  • 36 year old woman

  • Headaches for 6 months, vomiting, trouble walking

  • Exam showed signs of elevated intracranial pressure, hypertension, and cerebellar compression

  • MRI revealed a posterior fossa tumor, with herniated cerebellar tonsils and a cervical syrinx

  • Tumor was surgically removed

  • MRI 3 months later showed the cerebellar tonsils had returned to their normal position and shape and the syrinx had resolved


  • CM/SM due to a posterior fossa tumor is rare, but has been seen before

  • The tumor occupies space in the posterior fossa and forces the natural contents out of the skull

  • The cerebellar tonsils then block the normal CSF flow and a syrinx forms

  • Removing the source of the problem quickly can reverse the herniation and the syrinx.

Ed Note: For many years, Chiari was thought to be only a congenital malformation - meaning you are born with it. Unfortunately, some doctors still believe this is the case and give patients outdated information. This case is but one of many examples of acquired Chiari, many of which have been reversible upon fixing the underlying problem. This case also lends indirect support to the idea that most Chiari cases are due to a small posterior fossa. If a tumor essentially reduces the size of the posterior fossa, a malformation results.